The present invention relates to the technical field of a reservoir tank that is used in hydraulic brake systems and hydraulic clutch systems utilizing hydraulic pressure such as oil pressure and stores a hydraulic fluid and to the technical field of a brake system using the reservoir tank.
Conventionally, among vehicles such as automobiles, there are vehicles that employ hydraulic brake systems and hydraulic clutch systems utilizing hydraulic pressure. A master cylinder that generates hydraulic pressure and a reservoir tank that stores hydraulic fluid supplied to this master cylinder are used in these hydraulic brake systems and hydraulic clutch systems.
In order for the master cylinder to generate hydraulic pressure at times when hydraulic pressure is needed, it is necessary for a predetermined fluid volume of the hydraulic fluid to be stored in the reservoir tank. For this reason, usually a fluid volume detection sensor is disposed in the reservoir tank, and when the fluid volume in the reservoir tank falls below the predetermined fluid volume, this fluid volume detection sensor detects this and causes a fluid volume indicator to indicate this. Because of the indication of this fluid volume indicator, the reservoir tank is replenished with the hydraulic fluid and the fluid volume in the reservoir tank is ensured equal to or greater than the predetermined fluid volume.
Incidentally, when the vehicle tilts excessively, the reservoir tank also tilts excessively, and the hydraulic fluid in the reservoir tank flows (moves) downward. For this reason, the fluid level of the hydraulic fluid ends up fluctuating, and there is the fear that the fluid volume detection sensor will end up malfunctioning.
Therefore, conventionally, in Japanese Utility Model Registration No. 2,532,584, there is known a reservoir tank where, by using a partition plate having a notch portion to divide the reservoir tank into two chambers on a hydraulic fluid inlet side and a hydraulic fluid storage chamber side, fluctuations in the fluid level of the hydraulic fluid in the hydraulic fluid storage chamber are controlled even if the reservoir tank tilts.
However, in the reservoir tank disclosed in Japanese Utility Model Registration No. 2,532,584, the partition plate is formed separately from a lower half body of the reservoir tank, and this partition plate is disposed so as touch an inner peripheral surface of the lower half body. In disposing the partition plate on the inner peripheral surface of the lower half body in this way, it is necessary to form the partition plate in accordance with the shape and dimensions of the inner peripheral surface of the lower half body. For this reason, not only do shape management and dimension management of the partition plate become troublesome, but the fear that the partition plate will undergo positional displacement or dropping with respect to the lower half body is conceivable. In particular, in the reservoir tank disclosed in Japanese Utility Model Registration No. 2,532,584, because the partition plate is disposed on a curved portion between the hydraulic fluid inlet side and the hydraulic fluid storage chamber side, not only do shape management and dimension management of the partition plate become troublesome, but the fear that the partition plate will undergo positional displacement or dropping even more with respect to the lower half body is conceivable. Consequently, there are the problems that the number of parts increases, the configuration becomes complicated, and the number of assembly man-hours increases.